gistfile1.rb

class DigitalFaith::AmazonSimplePayTransactionsController < DigitalFaithController
  before_filter :find_instance
  
  def abandon
    AmazonSimplePayTransaction.create! attributes
    flash[:error] = "Your payment has been canceled"
    redirect_to polymorphic_failure_path
  end
  
  def prepare
  end
  
  def return
    AmazonSimplePayTransaction.create! attributes
    case params[:status]
    when "PS"
      flash[:notice] = "Your payment was successful"
      redirect_to polymorphic_success_path
    when "PF"
      flash[:error] = "Sorry — your payment failed"
      redirect_to polymorphic_failure_path
    when "PI"
      flash[:notice] = "Your payment is pending"
      redirect_to polymorphic_success_path
    when "ME"
      flash[:error] = "Sorry — payments are not available"
      redirect_to polymorphic_failure_path
    when "SE"
      flash[:error] = "Sorry — payment processing is unavailable. Please try again later"
      redirect_to polymorphic_failure_path
    else
      raise ArgumentError
    end
  end
  
private

  def attributes
    { :amazon_simple_payable_type => params[:amazon_simple_payable_type],
      :amazon_simple_payable_id   => params[:amazon_simple_payable_id],
      :transaction_id             => params[:transactionId],
      :reference_id               => params[:referenceId],
      :status                     => params[:status],
      :error_message              => params[:errorMessage],
      :operation                  => params[:operation],
      :payment_reason             => params[:paymentReason],
      :transaction_amount         => params[:transactionAmount],
      :transaction_date           => params[:transactionDate],
      :payment_method             => params[:paymentMethod],
      :recipient_name             => params[:recipientName],
      :buyer_name                 => params[:buyerName],
      :recipient_email            => params[:recipientEmail],
      :buyer_email                => params[:buyerEmail],
      :signature                  => params[:signature] }
  end
  
  def find_instance
    @instance = params[:amazon_simple_payable_type].constantize.find params[:amazon_simple_payable_id]
  end
  
  def polymorphic_failure_path
    case @instance.class.to_s
    when "Eventregistration"
      event_path @instance.event
    else
      raise ArgumentError
    end
  end

  def polymorphic_success_path
    case @instance.class.to_s
    when "Eventregistration"
      my_event_path @instance.event
    else
      raise ArgumentError
    end
  end

end

gistfile2.txt

module DigitalFaith::AmazonSimplePayTransactionsHelper

  def amazon_simple_pay_form(amazon_simple_payable_type, amazon_simple_payable_id, reference_id, amount)
    params = default_params(amazon_simple_payable_type, amazon_simple_payable_id).update \
      "amount"      => "USD #{amount}",
      "description" => reference_id,
      "referenceId" => reference_id
    haml_tag "form", :action => amazon_simple_pay_url, :method => "post" do
      params.each do |key, value|
        haml_concat hidden_field_tag(key, value)
      end
      haml_concat hidden_field_tag("signature", build_signature(params))
      haml_concat image_submit_tag("https://authorize.payments.amazon.com/pba/images/SMPayNowWithLogo.png")
    end
  end
  
  def amazon_simple_pay_url
    if production_stage?
      "https://authorize.payments.amazon.com/pba/paypipeline"
    else
      "https://authorize.payments-sandbox.amazon.com/pba/paypipeline"
    end
  end

  def build_message(params)
    params.keys.sort.inject("") { |string, key| string += "#{key}#{params[key]}" }
  end

  def build_signature(params)
    digest = OpenSSL::Digest::Digest.new "sha1"
    hmac = OpenSSL::HMAC.digest digest, "sekret", build_message(params)
    Base64.encode64(hmac).chomp
  end
  
  def default_params(amazon_simple_payable_type, amazon_simple_payable_id)
    { "abandonUrl"        => abandon_amazon_simple_pay_transaction_url(:amazon_simple_payable_type => amazon_simple_payable_type, :amazon_simple_payable_id => amazon_simple_payable_id),
      "accessKey"         => "sekret",
      "immediateReturn"   => "1",
      "processImmediate"  => "1",
      "returnUrl"         => return_amazon_simple_pay_transaction_url(:amazon_simple_payable_type => amazon_simple_payable_type, :amazon_simple_payable_id => amazon_simple_payable_id) }
  end
  
end